H.d eHee r Measurementsan dcomputation s onth e behaviouro fth einsecticide s azinphos-methyl anddimethoat ei nditche s ^F Centre for Agricultural Publishing and Documentation Wageningen - 1979 zot \ji~ Abstract Heer,H .d e (1979).Measurement san dcomputation so nth ebehaviou ro fth einsecticide s azinphos-methyl anddimethoat e inditches .Agric .Res .Rep . (Versl.landbouwk .Onderz . 884.Pudo cWageningen . ISBN9 022 0069 56.(xiv )+ 176p. ,5 5figs ,5 5tables ,14 2refs ,Eng .an dDutc hsummaries . Also:Doctora l thesisWageningen . Theunintentiona lpollutio no fsurfac ewate rwa sstudie ddurin gsprayin go fth einsec ­ ticidesazinphos-methy lan ddimethoat eo ntw ofrui tfarms .Spra ydrif tdepende d closelyo n theloca lsituation sa tth efrui tfarm s (windbreaks,distanc efro mtree st oditches ,paths ) ando nwa yo fapplication . Duringapplication , theconcentration so fbot hinsecticide s inwate ran di nditc h bottomswer emeasured .Method swer eadapte do rdevelope d forsampling ,extraction ,clean - -upan dgas-chromatography .Shortl yafte rspraying ,concentration swer esevera lhundred s ofm gm~3 .Th ehalf-live so fazinphos-methy lrange d from3 t o4 d ;thos efo rdimethoat e ranged from4 t o 13d . Waterflo wfro man dt oditc hsection swa sestimate d onbot hfrui tfarm sdurin gappli ­ cation.Flo wthroug hth editc hbotto mwa sestimate d asa closin gite mi na balanc eequa ­ tion.Al litem so fwate rbalanc ewer eintroduce d intocomputatio nmodel so fth ebehaviou r ofpesticide s insurfac ewate ran dbotto mmaterial .Th ese to fdifferentia lequation swa s solvednumericall yafte rprogrammin g inth ecompute rlanguag eCSM PIII .Simulatio no fa trialwit h lowdischarg efro ma siphon-linke d ditch indicated thatconversio no fbot hcom ­ pounds inwate rwa s 70-90%o fth emateria lbalances .Penetratio nint oth editc hbotto mwa s slow.Durin gwate rflo wthroug hth editches ,convectiv e transportan ddispersio nwer epre ­ dominant. Declineo fazinphos-methy l anddimethoat ewa sals omeasure d inoutdoo rtan ksystem s witha botto mlayer .Fluctuation s inp Han dvariation s inligh tpenetratio ninfluence dde ­ clinerates .Computation sfo rth etan ksyste mindicate d thatconversio ni nth ewate rcom ­ partmentwa sth emajo rite mi nmateria lbalance .Th ecompute dan dmeasure dmasse so fth e insecticidesi nth ebotto mlaye rwer eles stha n 10%o fth eamoun tadded . Conversionrate si nsurfac ewate ran di nsystem swit hanaerobi cbotto mmateria lwer e measured inth elaborator ya t 10an d2 0°C .Conversio ni nwate r inth edar kwa sslow ,wit h half-liveso fbot hcompound sa tabou t 100d a t2 0°C .Th econversio nrate so fazinphos - -methyli nanaerobi cbotto mmateria la t2 0° Cwa sabou t tentime sthos ei nsurfac ewater . Copperion swer ecatalyti ci nth econversio no fbot hinsecticide s inwater . Freedescriptors :adsorptio ncoefficient ,clean-up ,gas—liqui d chromatography,botto m material,conversion ,insecticides ,azinphos-methyl ,dimethoate ,watercourse ,ditch ,sam ­ pling,spra ydrift ,diffusion ,dispersion ,computations ,half-life ,rate-constant . ISBN 90 220 06956 The author graduated on 30Ma y 1979 asDocto r ind e Landbouwwetenschappen at the Agricultural University, Wageningen, the Netherlands , on a thesiswith the same title and contents. © Centre forAgricultura l Publishing and Documentation, Wageningen, 1979 No part of thisboo kma y be reproduced or published inan y form, by print, photoprint, microfilm or any othermean swithou t written permission from thepublishers . Contents List of symbols and units 1 Occurrence and origin of pesticides and herbicides in the aquatic environment 1 1.1 Chlorinatedhydrocarbo npesticide san d ijelatedcompound s 1 1.2 Cholinesteraseinhibitor s 2 1.3 Herbicides 4 1.4 Directapplicatio no fpesticide st osurfac e waters 5 1.5 Origino funintentiona lcontaminatio no i surfacewate rwit hpesticide s 7 2 Introduction to the present research program 10 2.1 Agriculturalemissio no fpesticide st oslur fac ewate r 10 2.2 Lay-outo fth epresen tresearc hprogra m 11 3 Review of the use and properties of azin\ tphos-methyl and dimethoate 13 3.1 Applicationo fazinphos-methy lan d dimeljhoatei nfrui tfarmin g 13 3.2 Physico-chemicalpropertie so fth ecompound s 14 3.3 Conversionrate san dpathway so fth eco npound s 14 3.4 Adsorptionan dleachin go fth e compoundsi nsoi l 18 3.5 Volatilizationo fth e compoundsfro mwate rbodie s 19 3.6 Sometoxicologica ldat ao fth ecompound s 21 4 Sampling of water and bottom material in ditches for analysis of pesticide residues 23 4.1 Shortrevie wo fdevice san dprocedure sflor watersamplin g 23 4.2 Watersamplin gi nth epresen tstud y 24 4.3 Shortrevie wo fdevice san dprocedure sfior samplingbotto mmateria l 25 4.4 Samplingo fbotto mmateria li nth epresen t study 26 S Procedures for chemical analysis for azinphos-épthyl and dimethoate in surface water and bottom material 28 5.1 Introduction 28 5.2 Methodsfo rextractio no fpesticide s frem surfac ewater s 28 5.3 Extractiono fazinphos-methy l fromwate i samples 29 5.4 Extractiono fdimethoat e fromwate rsample s 30 5.5 Methodsfo rextractio no fpesticide sf re m bottommateria l 30 5.6 Extractiono fazinphos-methy l frombotto m samples 31 5.7 Extractiono fdimethoat efro mbotto msa npie s 31 5.8 Methodsfo rclean-u po fextract s 31 5.9 Clean-upfo razinphos-methy lextract sfrja nwate r 32 5.10 Clean-upfo rdimethoat eextract sfro mwate r 32 5.11 Clean-upfo razinphos-methy lextract sfro mbotto mmateria l 32 5.12 Clean-upfo rdimethoat eextract sfro mbotto mmateria l 33 5.13 Concentrationmeasurement sb ygas—liqui dchromatograph y 33 5.14 Measuremento fazinphos-methy l 33 5.15 Measuremento fdimethoat e 35 6 Conversion rate and adsorption of azinphos-methyl and dimethoate in aquatic systems 36 6.1 Introduction 36 6.2 Conversionrat eo fazinphos-methy l inaqueou ssolution skep ti ndarknes s 36 6.3 Conversionrat eo fdimethoat ei naqueou ssolution skep ti ndarknes s 43 6.4 Conversionrat eo fazinphos-methy li nsystem so fbotto mmateria lan d surfacewate r 46 6.5 Conversionrat eo fdimethoat ei nsystem so fbotto mmateria lan d surfacewate r 49 6.6 Adsorptiono fazinphos-methy lo nbotto mmaterial s 51 6.7 Adsorptiono fdimethoat eo nbotto mmaterial s 54 6.8 Generaldiscussio n 55 7 Measurements in outdoor tanks: decline in water and penetration into bottom material 57 7.1 Introduction 57 7.2 Designo fth eoutdoo rtan ktrial s 57 7.3 Measuredrate so fdeclin ei nwate r 63 7.4 Measuredpenetratio nint obotto mmateria l 68 7.5 Generaldiscussio no noutdoo rtan ktrial s 70 8 Computation model on the behaviour of pesticides in a tank of water with a bottom layer 72 8.1 Introduction 72 8.2 Derivationo fth eequation s 72 8.3 Designo fth ecomputation s 74 8.4 Resultso fth esimulation so ftan ktrial s 75 8.5 Designo fth esimulatio nexperiment s 79 8.6 Resultso fth esimulatio nexperiment s 80 8.7 Generaldiscussio n 83 9 Measurements of azinphos-methyl and dimethoate in watercourses and farm ditches in the Kromme Rhine area and in the Lopikerwaard Polder 84 9.1 Introduction 84 9.2 Monitoringo fazinphos-methy lan ddimethoat ei nwatercourse san di n ditcheso nfrui tfarm sdurin g 1975 84 9.2.1 Descriptiono fsamplin gpoint san dprocedure s 84 9.2.2 Resultsan ddiscussio n 86 9.2.3 Preliminaryconclusion s 88 9.3 Fieldtrial so nth efat eo fazinphos-met^iy lan ddimethoat ei nditche s afterspra ydrif t 89 9.3.1 Introduction 89 9.3.2 Datao nth etria lfield si nth eLopikerw^ar d Polder 89 9.3.3 Measurementan dapproximatio no fth e iteiis ofth ewate rbalanc e 91 9.3.4 Surfacean dgroundwate r quality 96 9.3.5 Characterizationo fditc hbottom s 96 9.3.6 Sprayingdate san dprocedure si n197 6 101 9.3.7 Concentrationso fth einsecticide si nditc h water 102 9.3.8 Directmeasuremen to fspra ydrif tint od: . tches 106 9.3.9 Estimateo frat ecoefficient sfo rdeclin e 109 9.3.10 Concentrationso fth einsecticide si nsurfac ewate rnea rBenscho pan d Jaarsveldi n197 6 110 9.3.11 Preliminarymeasurement so fconcentratioil s ingroundwate r 111 9.3.12 Penetrationo fazinphos-methy lint obottcp m: material 112 9.3.13 Generaldiscussio nan dconclusion s 115 10 Computations on the behaviour of pesticides in a ditch compartment 116 10.1 Introduction 116 10.2 Ditchgeometr yan dderivatio no fequatioi s 116 10.3 Designo fth ecomputation san dvalue so fparameter s 120 10.4 Computedresult sfo rth efiel dtrial s 123 10.5 Designo fth esimulatio n experiments 132 10.6 Resultso fth esimulatio n experiments 132 10.7 General discussion 136 11 Measurements and computations on the behaviour of\ substances in ditches with flowing water 137 11.1 Introduction 137 11.2 Derivationo fequation sfo rone-dimensiorja lconvectio nan ddispersio no f substancesi nflowin gwate r 138 11.3 Dispersionmeasurement swit hdye s 140 11.4 Computationmode lfo rth ebehaviou ro fsubstance si nditche swit h flowingwate r 143 11.4.1 Derivationo fth eequation s 143 11.4.2 Lay-outo fth ecomputation san dvalue so f parameters 144 11.4.3 Resultso fsimulation sfo rth etrace r expsriment irimentss 146 11.4.4 Designo fth esimulatio nexperiment swit h pesticides 148 11.4.5 Resultso fsimulatio nexperiment swit h pesticides 148 11.5 Generaldiscussio n 149 Summary 151 Samenvatting 156 Appendices 161 References 171 List of symbols and units a dispersionconstan t (Equation40 ) 1) A averagewette dcross-sectiona lare ao fditc h m2) surfaceare ao ffirs tbotto mcompartmen ta tsediment—wate r m2) <Va-o interface widtha tbotto mo fditch ;widt ho fcompartmen t1 m) -3 massconcentratio no fsubstanc e infre eai r mgm massconcentratio no fsubstanc ei nbotto mmaterial :mas so f mgm substancedivide db yvolum eo fbotto mmateria